2. Bellringer 1) What do you know about electrons? 1) What do you know about electrons? 2) What do you think causes lightning? 2) What do you think causes lightning?

3. Agenda NOTES: Electricity NOTES: Electricity Static Charges Static Charges Electric Flow Electric Flow Insulators & Conductors Insulators & Conductors Design of Electric Wires Design of Electric Wires

4. Definition of Electricity Electricity is the movement of electrons. Electricity is the movement of electrons. Electrons are very tiny, negatively charged particles that are found in every object. Electrons are very tiny, negatively charged particles that are found in every object.

5. Charge Since electrons are negative, they change the charge of objects when they move. Since electrons are negative, they change the charge of objects when they move. When an object gains electrons it becomes negatively charged. When an object gains electrons it becomes negatively charged. When an object loses electrons it becomes positively charged. When an object loses electrons it becomes positively charged.

6. http://www.youtube.com/watch?v=mtY3M- mwdZY http://www.youtube.com/watch?v=mtY3M- mwdZY http://www.youtube.com/watch?v=mtY3M- mwdZY http://www.youtube.com/watch?v=mtY3M- mwdZY

7. Charged Objects Push & Pull Charged objects can push and pull each other, kinda like magnets. Charged objects can push and pull each other, kinda like magnets. Opposite charges attract each other Opposite charges attract each other Same charges repel each other Same charges repel each other

8. Direction of Electric Flow Electricity ALWAYS flows away from Negative charges or towards Positive charges. Electricity ALWAYS flows away from Negative charges or towards Positive charges. This is why batteries are labeled with + and – signs. Electricity comes out of the negative end and returns to the positive end. This is why batteries are labeled with + and – signs. Electricity comes out of the negative end and returns to the positive end.

10. Example 1: Lightning During Lighting, electrons flow away from the negatively charged clouds towards the ground During Lighting, electrons flow away from the negatively charged clouds towards the ground

12. Example 2: Balloon Stuck on Wall http://phet.colorado. edu/en/simulation/b alloons http://phet.colorado. edu/en/simulation/b alloons http://phet.colorado. edu/en/simulation/b alloons http://phet.colorado. edu/en/simulation/b alloons

13. Conductors and Insulators Some materials allow electrons to flow through them very easily, while others do not allow electrons to flow. Some materials allow electrons to flow through them very easily, while others do not allow electrons to flow. Materials that allow electricity to pass through them are called conductors. All metals are conductors. Materials that allow electricity to pass through them are called conductors. All metals are conductors. Materials that do not allow electricity to pass through them are called insulators. Rubber and Wood are insulators. Materials that do not allow electricity to pass through them are called insulators. Rubber and Wood are insulators.

14. Design of Electrical Cords Electrical cords contain conductors and insulators. Electrical cords contain conductors and insulators. There is copper inside the wire to carry electricity, and a rubber coating to prevent getting shocked. There is copper inside the wire to carry electricity, and a rubber coating to prevent getting shocked.

15. Grounding Wire The “Third Prong” of an electric cord does not carry electricity. It carries overloads into the ground in order to prevent shocking people. The “Third Prong” of an electric cord does not carry electricity. It carries overloads into the ground in order to prevent shocking people.

16. How Tasers Work Brain uses electricity to tell your muscles to move. Brain uses electricity to tell your muscles to move. A stun gun forces all of your muscles to squeeze. A stun gun forces all of your muscles to squeeze. There is a small risk for people with weak hearts. There is a small risk for people with weak hearts.

17. Assignments 11 Review Questions